[Bug] Performance degrades for large DOM trees

[Kitenite]

Describe the bug

There's a lot of DOM processing happening which makes editing slow for large,nested DOM trees.

Try with example:
https://www.google.com/search?sca_esv=f34a7ccbd9a4492c&sca_upv=1&q=sport+climbing+combined+olympics&oi=ddle&ct=348045702&hl=en&sa=X&ved=0ahUKEwi4_Pys7OWHAxWqFlkFHVwPFvQQPQgC&biw=1362&bih=823&dpr=1

[Kitenite]

This is isolated down to the user of getDeepElement and how when using with deep nested DOM it can have a large performance hit